You will get a message that says "network-manager set to manually installed" and then I think you can remove it without removing everything else.

If that doesn't work, check what other packages task-cinnamon-desktop installs, and install the packages manually instead of the task- package. (check task-desktop and cinnamon-desktop-environment first - these are also metapackages) but don't install network-manager.

After looking some more, I see that the cinnamon package recommends network-manager-gnome, which in turn depends on network-manager. If you install the cinnamon desktop with individual packages instead of the task package, you could do